Producing method for grater

ABSTRACT

A producing method for grater includes: coating etching resistant layers ( 2, 3 ) with etching openings ( 5, 6 ) on the front surface and the rear surface of a metal plate ( 1 ), the opening ( 6 ) on the rear surface being larger than the opening ( 5 ) on the front surface, etching liquid attacking the metal plate ( 1 ) via the etching opening ( 6 ) on the rear surface and corroding towards the etching opening ( 5 ) on the front surface without pressure, thereby etching the exposed area in the etching opening ( 5, 6 ), then, forming a sharp edge ( 7 ) near the front surface and a curved surface along the discharging direction. The edge of the grater produced by the method is sharp, and cutting is smooth.

FIELD OF THE INVENTION

The present invention relates to a method for forming a plurality ofcutting edges on a thin metal plate.

BACKGROUND OF THE INVENTION

A grater is normally used for shredding foods such as vegetables, cheeseor chocolate. The grater is a tool with cutting perforations on a thinmetal plate. The foods such as radish to be shredded is applied on thefront surface of the metal plate and moved with respect to the cuttingperforations to enable the foods to be shredded and then discharged fromthe rear surface of the metal plate.

The traditional method for manufacturing the grater is to punch a thinmetal plate to form a plurality of cutting perforations thereon. Thecutting perforations obtained through punching can not form sharpcutting edges and normally have burrs. It is thus difficult for thegrater manufactured by this method to shred the foods into continuousand complete filaments or pieces, and may result in obstruction of theperforations easily. Moreover, in order to prevent the grater fromrusting and thus polluting the foods, most of the known graters are madeof stainless steel. However, the stainless steel has high toughness, andthe punching process is thus relatively difficult.

The known chemical etching method for manufacturing the grater includes:covering an anti-corrosion protection layer on a thin metal plate;forming a plurality of openings in a desired shape on the protectionlayer; washing or soaking the metal plate with chemical corrosive liquidto enable the metal surface exposed from the opening to be corroded intoa desired blade shape; and stamping the metal plate to allow the bladesto protrude from the metal plate, such that the grater is obtained. TheU.S. Pat. No. 5,100,506 discloses several chemical etching methods formanufacturing the grater. As shown in FIGS. 1 to 6, the reference number1 refers to a metal plate, the reference number 2 refers to a protectionlayer on the front surface of the metal plate, the reference number 3refers to a protection layer on the rear surface, the reference number 4refers to the etching spray, the reference number 5 refers to theetching opening on the front surface, the reference number 6 refers tothe etching opening on the rear surface, the reference number 7 refersto the cutting edge of the blade obtained by etching, the referencenumber 8 refers to the base of the cutting edge, and the referencenumber 9 refers to the root of the blade.

In the etching method illustrated in FIG. 1, the upper and lowersurfaces of the metal plate are both provided with anti-corrosionprotection layers, and the etching openings on these two protectionlayers are correspondingly overlapped, the etching liquid corrodes themetal plate from both surfaces simultaneously, and after etching, theobtained blade is shown in FIG. 2, a cutting edge 7 is formed at themiddle of the section of the metal plate. This cutting edge is slightlyprotruded and not sharp, and a blade base 8 is provided on each side ofthe cutting edge, the surface of the blade base is almost the crosssection of the metal plate, therefore, the cutting edge is not sharp,and the surface of the blade base will block the discharging of shreddedfoods and result in obstruction during shredding of foods, and irregularshape of shredded foods.

In the method illustrated in FIG. 3, a protection layer with etchingopenings thereon is formed on one surface of the thin metal plate, andetching liquid corrodes the metal plate from the etching openings. Afteretching, the obtained blade is shown in FIG. 4. It is still impossibleto a sharp cutting edge, and a curved surface against the dischargingdirection is formed at the blade base, the shredded foods will beblocked and pressed by the curved surface, and therefore the dischargingis still not smooth and it is difficult to obtain continuous filamentsor pieces.

The method illustrated in FIG. 5 is that a protection layer is formed oneach side of the metal plate, but etching openings are only formed onthe protection layer of the rear surface, and the corrosion liquidcorrodes the metal plate from the rear surface. Since the metal plate iscorroded at one surface and the other surface is covered with aprotection layer. With this method, a relatively sharp cutting edge canbe obtained. However, the curved surface of the blade base is stillformed, as shown in FIG. 6, and this curved surface will still block thedischarging of the shredded foods. Thus, it is still difficult to obtaincontinuous and complete filaments or pieces. Furthermore, since thecutting edges are formed on the upper surface of the metal plate, thecutting edge is not inclined with respect to the upper surface, which isnot good for separating the filaments or pieces from the main body ofthe foods.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method forproducing a grater, which can obtain sharp cutting edges, ensuresobjects to be cut into continuous and complete filaments or pieces, andfacilitates smooth discharging of them.

To achieve the above object, the present invention provides a method forproducing a grater, comprising:

-   -   a. coating etching resistant protection layers on both front and        rear surfaces of a thin metal plate;    -   b. forming etching openings on the etching resistant protection        layers on the front and rear surfaces of the metal plate        according to a desired blade shape, the etching opening on the        front surface of the metal plate is staggered with respect to        the etching opening on the rear surface of the metal plate to        ensure the etching opening on the rear surface of the metal        plate to be widen at the side where a blade root is located with        respect to the etching opening on the front surface of the metal        plate;    -   c. attacking the metal plate via the etching openings on the        rear surface by using etching liquid that is capable of etching        metal, and soaking the etching openings on the front surface        without pressure, thereby etching areas of the metal plate        exposed from the etching openings, thus forming blades;    -   d. removing the protection layers and washing the metal plate;    -   e. stamping the metal plate to enable cutting edges of the        blades to be protruded from the metal plate.

In the producing method of the present invention, because the etchingopenings on both sides of the metal plate are staggered with respect toeach other, and the opening on the rear surface is larger than theopening on the front surface, and during the etching process, theetching liquid attacks the metal areas exposed from the openings on therear surface under pressure to enable the rear surface to be rapidlyetched, while the front surface is slowly etched by the etching liquidwithout pressure. After etching, a sharp cutting edge is formed at theposition where the cross section of the metal plate is close to thefront surface, and there is a slope between the cutting edge and thefront surface, which facilitates the separating of the filaments orpieces from the main body of the foods. Furthermore, because the etchingopening on the front surface is staggered with respect to the etchingopening on the rear surface, the blade base is relatively long and acurved surface is formed along the discharging direction such that thecutting is smoothed. With the grater of the present invention, thecutting edge is sharp, and the cutting is smooth, which allow the foodsto be shredded into continuous and complete filaments or pieces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a chemical etching method for producing agrater;

FIG. 2 is a schematic view of a product obtained from the method of FIG.1;

FIG. 3 is a schematic view of another chemical etching method forproducing a grater;

FIG. 4 is a schematic view of a product obtained from the method of FIG.3;

FIG. 5 is a schematic view of another chemical etching method forproducing a grater;

FIG. 6 is a schematic view of a product obtained from the method of FIG.5;

FIG. 7 is a schematic view of a method for producing a grater accordingto the Embodiment 1 of the present invention;

FIG. 8 is another schematic view of a method for producing a grateraccording to the Embodiment 2 of the present invention;

FIG. 9 is the product obtained from the method of FIG. 7 and FIG. 8;

FIG. 10 is a partial enlarged view showing the cutting edge of the bladeof FIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Embodiment 1

A method for producing a grater of the Embodiment 1 is shown in FIGS. 7,8 and 9, the method includes:

-   -   a. etching resistant protection layers 2, 3 are coated on both        front and rear surfaces of a thin metal plate; photoactive ink        is applied on the surfaces of a clean and dry thin metal plate,        and an oven is used for drying the ink on the surfaces of the        metal plate;    -   b. etching openings 5, 6 that are corresponding to the desired        blade shape are formed on the protection layer photoactive ink        on both surfaces of the metal plate by the known techniques of        image developing, fixing and exposing; the etching opening 6 on        the rear surface of the metal plate is staggered with respect to        the etching opening 5 on the front surface of the metal plate        such that the etching opening on the rear surface of the metal        plate is widen at the side where the blade root 9 is located        with respect to the etching opening on the front surface of the        metal plate;    -   c. the metal plate is attacked via the etching openings on the        rear surface by etching liquid that is capable of etching metal,        and the etching liquid soaks the etching openings on the front        surface without pressure, thereby the exposed metal areas in the        etching openings are etched, thus blades are formed, wherein the        etching liquid that is capable of etching metal is the chemical        etching liquid in the prior art which includes 70-80wt % of        ferric trichloride, 10-20 wt % hydrochloric acid, 2-4 wt % of        water and 1-2 wt % of nitric acid;    -   d. the protection layers are removed, and the metal plate is        washed;    -   e. the metal plate is stamped to enable cutting edges of the        blades to be protruded from the metal plate.

In the producing method of this embodiment, as shown in FIGS. 7, 8 and9, since the etching openings on both sides of the metal plate arestaggered with respect to each other, and the etching opening on therear surface is larger than the etching opening on the front surface atthe position where the blade root 9 is located. During the etchingprocess, the chemical corrosive liquid attacks the metal surface exposedfrom the opening on the rear surface under pressure to allow the rearsurface to be corroded quickly, while the front surface is corrodedslowly by the chemical corrosive liquid without pressure. After thecorrosion, a sharp cutting edge is formed at the position where thecross section of the metal plate adjacent to the front surface of themetal plate, and the cutting edge has a slope 10 with respect to thefront surface, and the length of the slope is around 0.03 mm, whichfacilitates the separating of the filaments or pieces from the main bodyof the foods. Furthermore, since the openings on the front and rearsurfaces are staggered with respect to each other, a blade base with along curved surface along the discharging direction is formed, and thusthe shredding is smoothed. With this grater, the cutting edge is sharp,the shredding is easy and smooth, and the foods can be shredded intocontinuous and complete filaments or pieces.

It should be emphasized that in the step b, upon conforming to thecondition that the etching openings on both sides of the metal plate arestaggered and the etching opening on the rear surface is larger than theetching opening on the front surface at the position where the bladeroot 9 is located, the size of the openings on the front and rearsurfaces can be the same or different, for example, the projection ofthe etching opening on the rear surface onto the front surface can coverthe etching opening on the front surface completely.

Embodiment 2

In the method for producing the grater of this embodiment, the step cis: the metal plate is disposed in an electrolytic cell, the metal plateis connected to the positive pole of a DC power supply to enable themetal plate to be the electrolytic anode, and the etching liquid foretching the metal is the electrolytic liquid. The electrolytic liquidattacks the metal plate via the opening on the rear surface of the metalplate, while the corrosive liquid flows randomly on the etching openingof the front surface and etches the metal surface exposed from theetching opening to obtain the blade with the desired shape. The othersteps are the same as that of the Embodiment 1.

The electrolytic liquid can be NaCl, KCl, Na₂SO₄, etc.

In this embodiment, the non-toxic and harmless electrolytic liquidsubstitutes the acidic corrosive liquid that is harmful to human bodyand pollutional to the environment.

Embodiment 3

In the method for producing the grater of this embodiment, in the stepsa and b, the anti-corrosion protection layer with etching openings isformed by printing a layer of etching resistant ink layer with openingsonto the metal plate directly via printer. The other steps are the sameas that of the Embodiment 2. With this method, the manufacturing processis simple, rapid, with high yield and reduces the cost greatly.

1. A method for producing a grater, comprising: a. coating etchingresistant protection layers on both front and rear surfaces of a thinmetal plate; b. forming etching openings on the etching resistantprotection layers on the front and rear surfaces of the metal plateaccording to a desired blade shape, the etching opening on the frontsurface of the metal plate is staggered with respect to the etchingopening on the rear surface of the metal plate to ensure the etchingopening on the rear surface of the metal plate to be widen at the sidewhere blade roots are located with respect to the etching opening on thefront surface of the metal plate; c. attacking the metal plate via theetching openings on the rear surface by using etching liquid that iscapable of etching metal, and soaking the etching openings on the frontsurface without pressure, thereby etching metal areas of the metal plateexposed from the etching openings, thus forming blades; d. removing theprotection layers and washing the metal plate; e. stamping the metalplate to enable cutting edges of the blades to be protruded from themetal plate.
 2. The method of claim 1, wherein the metal plate isdisposed in an electrolytic cell, both poles of a DC power supply arerespectively connected to the metal plate and the electrolytic liquid,and the etching liquid for etching the metal is the electrolytic liquid,the electrolytic liquid attacks the metal plate via the etching openingson the rear surface of the metal plate, while the electrolytic liquidflows randomly on the etching openings of the front surface and etchesmetal surface exposed from the etching openings to obtain the blades. 3.The method of claim 1, wherein the anti-corrosion protection layer withetching openings is formed by printing a layer of etching resistant inklayer with openings onto the metal plate directly.
 4. The method ofclaim 1, wherein the etching openings of the protection layers have thesame size.
 5. The method of claim 1, wherein the projection of theetching opening on the rear surface onto the front surface covers theetching opening on the front surface completely.